Sage Reference Manual: Matrices and Spaces of Matrices - Mirrors

Sage Reference Manual: Matrices and Spaces of Matrices, Release 6.1.1
The default is to check whether the any index in drows is out of range.
sage: A.delete_rows([-1,2,4])
Traceback (most recent call last):
...
IndexError: [4, -1] contains invalid indices.
sage: A.delete_rows([-1,2,4], check=False)
[ 0 1 2]
[ 3 4 5]
[ 9 10 11]
TESTS:
The list of indices is checked.
sage: A.delete_rows(’junk’)
Traceback (most recent call last):
...
TypeError: The argument must be a list or a tuple, not junk
AUTHORS:
• Wai Yan Pong (2012-03-05)
dense_columns(copy=True)
Return list of the dense columns of self.
INPUT:
•copy - (default: True) if True, return a copy so you can modify it safely
EXAMPLES:
An example over the integers:
sage: a = matrix(3,3,range(9)); a
[0 1 2]
[3 4 5]
[6 7 8]
sage: a.dense_columns()
[(0, 3, 6), (1, 4, 7), (2, 5, 8)]
We do an example over a polynomial ring:
sage: R. = QQ[ ]
sage: a = matrix(R, 2, [x,x^2, 2/3*x,1+x^5]); a
[ x x^2]
[ 2/3*x x^5 + 1]
sage: a.dense_columns()
[(x, 2/3*x), (x^2, x^5 + 1)]
sage: a = matrix(R, 2, [x,x^2, 2/3*x,1+x^5], sparse=True)
sage: c = a.dense_columns(); c
[(x, 2/3*x), (x^2, x^5 + 1)]
sage: parent(c[1])
Ambient free module of rank 2 over the principal ideal domain Univariate Polynomial Ring in
TESTS:
Check that the returned rows are immutable as per trac ticket #14874:
103